1. Field of the Invention
The invention relates to refrigerator defrosting systems and is particularly directed to a defrosting arrangement continuously effective to minimize the accumulation of frost on evaporator tubing.
2. Description of the Prior Art
It is known to use cyclically operated heaters in refrigerators to remove frost from tubing carrying a refrigerant, but they have not been found entirely satisfactory for the purpose, because of the additional power required for their operation, and because the frost which accumulated between operative periods of the heaters prevented the refrigeration system from operating at optimum efficiency. Furthermore, electrical heating elements which are reliable and not wasteful of electrical energy in the enviornment of a refrigerator have not been generally available. Electrical tape, for example, which was at first thought to be especially suitable as a heating element in a refrigerator, since it could be easily wrapped around a section of tubing on which frost tended to accumulate proved to be unsatisfactory because it would frequently short and burn out, resulting in expensive shut downs and repairs.
It is preferable to use hot refrigerant for defrosting and it is a prime object of this invention to minimize the accumulation of frost in a refrigerator, utilizing hot refrigerant continuously circulated in heat transfer loops of the refrigeration system in a manner such as to effect a reduction in power required to operate the refrigerator.